<TITLE>
BRL-CAD Overview
</TITLE>
<BODY>
<H1>BRL-CAD Overview</H1>
<H2>What Is BRL-CAD?</H2>
The BRL-CAD Package is a powerful Constructive Solid Geometry (CSG)
based solid modeling system.  BRL-CAD includes an interactive geometry
editor, a ray tracing library, two ray-tracing based lighting models,
a generic framebuffer library, a network-distributed image-processing
and signal-processing capability, and a large collection of related
tools and utilities.  The software
has been undergoing continuous development since 1979.
<P>
BRL-CAD supports a great variety of geometric representations, including
an extensive set of traditional CSG primitive solids such as blocks,
cones and torii, solids made from closed collections of Uniform B-Spline
Surfaces as well as Non-Uniform Rational B-Spline (NURBS) Surfaces,
purely faceted geometry, and n-Manifold Geometry (NMG). All geometric
objects may be combined using boolean set-theoretic operations such as
union, intersection, and subtraction.
<P>
Material properties and other attribute properties can be associated
with geometry objects. This combining of material properties with
geometry is a critical part of the link to applications codes. BRL-CAD
supports a rich object-oriented set of extensible interfaces by means of
which geometry and attribute data are passed to applications.
<P>
BRL-CAD is used at over 800 sites located throughout the world.
It is provided in source code form only, and totals more than 280,000
lines of "C" code.
<P>
A few of the applications linked to BRL-CAD include:
<P>
<UL>
<LI> Optical Image Generation (including specular/diffuse reflection,
refraction, multiple light sources, and articulated animation)
<LI> An array of military vehicle design and evaluation V/L Codes
<LI> Bistatic laser analysis
<LI> Predictive Synthetic Aperture Radar Codes (including codes due to ERIM)
<LI> High-Energy Laser Damage
<LI> High-Power Microwave Damage
<LI> Weights and Moments-of-Inertia
<LI> Neutron Transport Code
<LI> PATRAN [TM] and hence to ADINA, EPIC-2, NASTRAN, etc.
for structural/stress analysis
<LI> X-Ray image calculation
</UL>

<h2>System Requirements</h2>
<p>
BRL-CAD requires the UNIX(tm) operating system.  It has been ported to more
than a dozen product lines from workstations to supercomputers, including:
<UL>
<LI>Alliant FX/8 and FX/80, Alliant FX/2800
<LI>Apple Macintosh II running AUX
<LI>Convex C1
<LI>Cray-1, Cray X-MP, Cray Y-MP, Cray-2
<LI>Digital Equipment VAX
<LI>Gould/Encore PN 6000/9000
<LI>IBM RS/6000
<LI>Intel-based ``PC'' machines running:
	<UL>
	<LI>BSD/OS
	<LI>FreeBSD/OpenBSD/NetBSD
	<LI>Linux
	</UL>
<LI>Pyramid 9820
<LI>Silicon Graphics 3030 through O2/Origin Series
<LI>Sun Microsystems Sun-3 and Sun-4 ``SparcStation''.
</UL>
Porting to other UNIX systems is
very easy, and generally requires only one or two man-days of effort.
<P>
Some users report being able to build the package under VAX/VMS(tm)
with some expenditure of effort.
